1. Field of the Invention
The present invention relates to a method of fabricating a magnetic head slider, and more particularly relates to a method of forming a protective film on an air bearing surface.
2. Description of the Related Art
In a hard disk device, a magnetic head slider (hereinbelow referred to as a “slider”) flies over the recording medium (hard disk or magnetic disk) with only a slight gap interposed to read data from the recording medium and to write data to the recording medium.
The magnetic head for reading data from the recording medium and writing data to the recording medium must be protected from corrosion in a wide variety of environments and must be protected from collision with the recording medium. Therefore, a protective film composed of, for example, diamond-like-carbon (DLC) is formed on the surface of the slider that faces the recording medium, i.e., the air bearing surface.
However, the development of recording media with higher recording densities in recent years has been accompanied by a need for a reduction of the gap between the slider and the recording medium. To be more accurate, this requirement means a decrease of the spacing between the recording medium and the reproduction element and the spacing between the recording medium and the recording element. Decreasing the film thickness of the protective film is effective for this purpose. However, because the protective film is formed on the surface of the slider in which unevenness occurs, the film thickness tends to be easily influenced by unevenness. In places where the film thickness is reduced, pinholes tend to occur in the protective film, and these pinholes serve as the origin of corrosion of the underlying reproduction element and recording element. Accordingly, merely reducing the film thickness of the protective film to reduce the spacing between the slider and recording medium is problematic.
In view of this problem, JP-A-2007-026506 discloses a method of forming a protective film of a slider. According to this method, a silicon (Si) film and a DLC film are deposited in that order on the air bearing surface of the slider. Processing of the air bearing surface is next carried out in this state, following which the silicon film and DLC film are entirely removed. The processing of the air bearing surface involves forming on the air bearing surface an uneven portion that controls the air flow that enters the space between the slider and recording medium when the recording medium is being driven and that thereby controls the flying characteristic of the slider. A protective film is then formed again and an ion beam is irradiated from an oblique angle to remove a portion of the protective film.
However, a protective film with superior corrosion resistivity properties still cannot be formed even when this type of method is used. This problem is presumed to arise because, even when etching of only the silicon film and DLC film is intended, etching damage inevitably remains on the underlying recording element and reproduction element and affects the reliability of the elements. In particular, increasing the thickness of the protective film to raise the corrosion resistivity property is precluded by the demand for reduction of the spacing between the recording medium and the recording element and the spacing between the recording medium and the reproduction element for the future development of even higher recording densities.